1	# src/lint: the interpreter for `bolt` itself. It starts from a World
2	# holding the paths it was given and the working directory
3	# (src/lint/world.bend), then loops: it asks
4	# the planner (src/lint/plan.bend) what is still open, answers each question
5	# by IO, a directory listed through src/walk/ and a file read through
6	# src/lsp/files/ (a path src/walk/ calls a directory is answered as one,
7	# not read), and adds the answers to the World, until nothing is left to
8	# ask. Then it prints the planner's lines and exits with its status. It
9	# decides nothing: which files are linted, which bolt.bend grades each
10	# finding, and what is printed are the planner's. That it answers and prints
11	# faithfully is trusted, not proved: it is kept small enough to review line
12	# by line, as is every interpreter here (src/check.bend, src/lsp/server.bend).
13	import Base
14	import ./lint/world.bend as W
15	import ./lint/plan.bend as Plan
16	import ./lsp/files/disk.bend as Disk
17	import ./walk/disk.bend as WalkDisk
18	import ./status.bend as Status
19	import ./lazy/lazy.bend as Lazy
20	
21	# a file's text as an answer
22	def read.answer(mm: Maybe<&2, String>) -> W.Answer:
23	  match mm:
24	    case None{}:
25	      W.Unread{}
26	    case Some{text}:
27	      W.Read{text}
28	
29	# a path's text as an answer: a directory has none, and a file is read
30	def text.answer(dir: Bool, path: String) -> IO(W.Answer):
31	  match dir:
32	    case True{}:
33	      IO.pure(W.Answer, W.Directory{})
34	    case False{}:
35	      do IO<W.Answer>:
36	        mm : Maybe<&2, String> <- Disk.read(path)
37	        return read.answer(mm)
38	
39	# one question, answered
40	def answer(ask: W.Ask) -> IO(W.Answer):  # noqa: L001 IO driver
41	  match ask:
42	    case W.Entries{dir}:
43	      do IO<W.Answer>:
44	        es : List<&2, String> <- WalkDisk.entries(dir)
45	        return W.Listed{es}
46	    case W.Contents{+path}:
47	      do IO<W.Answer>:
48	        dir : Bool <- WalkDisk.is_dir(path)
49	        text.answer(dir, path)
50	
51	# every question, answered, in order
52	def answer.all(asks: List<&2, W.Ask>) -> IO(List<&2, W.Reply>):
53	  match asks:
54	    case Nil{}:
55	      IO.pure(List<&2, W.Reply>, [])
56	    case Con{+ask, rest}:
57	      do IO<List<&2, W.Reply>>:
58	        a : W.Answer <- answer(ask)
59	        more : List<&2, W.Reply> <- answer.all(rest)
60	        return W.Reply{ask, a} <> more
61	
62	# the World with more answers in it
63	def more(world: W.World, rs: List<&2, W.Reply>) -> W.World:
64	  W.World{paths, cwd, replies} = world
65	  W.World{paths, cwd, List.append(&2, W.Reply, replies, rs)}
66	
67	# each line printed
68	def print_all(lines: List<&2, String>) -> IO(Unit):  # noqa: L001 IO driver
69	  match lines:
70	    case Nil{}:
71	      IO.pure(Unit, Unit{})
72	    case Con{l, t}:
73	      do IO<Unit>:
74	        IO.print(l)
75	        print_all(t)
76	
77	# a plan, carried out: its lines printed, then its exit status
78	def exec(pl: Plan.Plan) -> IO(Unit):  # noqa: L001 IO driver
79	  Plan.Plan{lines, exit} = pl
80	  do IO<Unit>:
81	    print_all(lines)
82	    Status.stop(U32.is_gt(exit, 0))
83	
84	# the planner's questions answered and the loop gone round again, or, when
85	# there are none, its plan carried out
86	def loop.step(asks: List<&2, W.Ask>, +world: W.World, go: W.World -> IO(Unit)) -> IO(Unit):
87	  match asks:
88	    case Nil{}:
89	      exec(Plan.plan(world))
90	    case Con{a, rest}:
91	      do IO<Unit>:
92	        rs : List<&2, W.Reply> <- answer.all(a <> rest)
93	        go(more(world, rs))
94	
95	# the loop, under fuel: the walk's bound, plus a round for the texts and one
96	# to plan. Every round adds at least one answer, since the planner never asks
97	# what the World answers already.
98	def loop(fuel: Nat, +world: W.World) -> IO(Unit):  # noqa: L001 IO driver
99	  match fuel:
100	    case 0n:
101	      IO.die(Unit, 1, "bolt: the lint kept asking")
102	    case 1n+f:
103	      loop.step(Plan.wants(world), world, ww => loop(f, ww))
104	
105	# the lint from a working directory; none that can be named is fatal, as no
106	# relative path could be resolved against it
107	def run.from(paths: List<&2, String>, +cwd: String) -> IO(Unit):
108	  Lazy.stop(IO(Unit), String.is_empty(cwd), IO.die(Unit, 1, "bolt: cannot name the working directory"),
109	    _u => loop(Nat.add(Plan.limit(), 2n), W.World{paths, cwd, []}))
110	
111	# the linter, over the files given, or the tree below
112	def run(paths: List<&2, String>) -> IO(Unit):  # noqa: L001 IO driver
113	  do IO<Unit>:
114	    cwd : String <- WalkDisk.cwd()
115	    run.from(paths, cwd)